More than three-quarters of registered Republican voters in Texas and roughly as many tea party supporters say immigrants who are here illegally should be deported immediately, a policy pushed by presumptive GOP presidential nominee Donald Trump, according to a new survey.

The poll by the University of Texas/Texas Politics Project, released Tuesday, shows Trump’s most controversial policies, including building a border wall and banning Muslims from entering the U.S., are overwhelmingly favored among Texas conservatives.

The same poll, however, shows Trump leads likely Democratic candidate Hillary Clinton by only 8 percentage points in Texas. Overall, 41 percent of the state’s voters support Trump and 33 percent favor Clinton. Twenty-seven percent said they either prefer someone else or hadn’t thought about it enough.

Deporting the nation’s 11 million immigrants here illegally would require at least $400 billion in new federal spending and reduce U.S. gross domestic product by about $1 trillion, a study by the American Action Forum, a free-market think tank in Washington D.C., has found.

Seventy-six percent of “mainline” Republicans and 77 percent of tea party supporters agree with the idea, according to the Texas poll. Seventy-one percent of Democrats disagree.

Most Republicans, 62 percent, also oppose comprehensive immigration reform when it includes a pathway to citizenship and 52 percent are against it even if it just contains a way to live in the U.S. legally. Three-quarters of Democrats support the former; almost as many favor the latter.

A majority of Texans, buoyed by overwhelming Republican support, approve of Trump’s two most hot-button plans.

Fifty-two percent of Texans and 76 percent of Republicans favor building a wall on the border. Trump has said it would cost as much as $12 billion and that Mexico would pay for it, though that country’s leaders have dismissed such an idea as ludicrous. An economist for one of the nation’s largest construction firms told the Washington Post that a wall would likely cost about $25 billion — three times Trump’s estimate.

The idea of banning Muslims from entering the United States was similarly popular — 52 percent of Texas voters supported the idea — and fell along partisan lines with 67 percent of Democrats against it and 76 percent of Republicans favoring it.

Both Democratic opposition and Republican support increased at least 10 points since the pollsters asked about the issue in February.

Most legal experts agree that banning Muslims would likely be against the constitution because it is religious discrimination. A Trump presidency, however, could possibly have the authority to suspend immigration from largely Muslim countries with a “proven history of terrorism,” as he said this month.

That’s because a provision of immigration law grants the president the ability to suspend entry of noncitizens whose arrival “would be detrimental to the interests of the United States.”

In their analysis, the pollsters said support of Trump’s ideas among Texans predates the billionaire’s ascent and has been reflected in previous election results and recent legislative politics.

Certainly, his rhetoric is resonating with them.

“Whatever the distaste with which some Republican leaders view Trump’s proposals and the rhetoric he has and continues to use to pitch them, they appear to have become part of the firmament of the partisan universe in the presidential campaign — and are finding an accepting audience among Republicans in Texas,” note Jim Henson and Joshua Blank, who conducted the poll.

It surveyed 1,200 registered voters online between June 10 and June 20 and has a margin of error of plus or minus 2.8 percentage points. Telephone polls are generally thought to be more accurate than online surveys.